Krystyna Cedzynska

Plasma Destruction of Toxic Chloroorganic Wastes Towards Zero Residues

Abstract The most effective decomposition methods were chosen for chloroorganic compounds on the basis of thermochemical calculations. The two rotating arc plasma reactors have been applied in these waste destruction processes. Gaseous products with high calorific values were obtained from simple chloroorganic compounds. PCB congeners with a high chlorine content were melted with chosen oxides yielding a useful solid product.

IODIDE FOR THE PHYTOEXTRACTION OF MERCURY CONTAMINATED SOIL

Garden cress (Lepidium sativum) plants were grown in soil artificially contaminated with mercury salts: HgCl2, HgSO4, Hg(NO3)2. Laboratory investigations were performed to evaluate the accumulation of Hg in roots, stems and leaves of the plant before/after iodide amendment to the soil. The result showed that Lepidium sativum accumulated mercury from soil, but overall maximum concentration of mercury was found in roots of the plants. Iodide application to the soil caused mercury mobilisation and thereby increased the bioavailability of Hg in soil, which effected in increase of Hg concentration in the plant. Effective accumulation by whole plant and by shoots was higher compared to the process, which was carried out without iodide addition. Enhancing the phytoextraction by addition of potassium iodide increases the efficiency of the process. In spite of using soil amendment (KI), over 80% of total mercury concentration in Lepidium sativum was accumulated in roots of the plant. Therefore this plant has a potential to be a good phytostabilizer. Lepidium sativum is an important medicinal plant and a vegetable consumed by people, for that reason there is a possibility of including Hg into food-chain. Toxicological risks should be consider before using this plant for cleaning soil contaminated by Hg.

Plasma Treatment of Inorganic Waste

The fully friendly to the environment and the most cost-effective thermal plasma system for waste destruction are here presented. The proposed solutions are directed towards zero emission of any hazardous residuals. This results in no longer waste storage in landfills if the plasma technologies are widely commercialised. The final product (vitrified material) obtained after the plasma treatment is environmentally acceptable. It can return to the environment as an aggregate in the construction industry.

Thermal and Biological Degradation of Sites Contaminated by Transformer Oil

The destruction of waste transformer oil contaminated with some toxic compounds (e.g., PCB’s) was investigated in two ways: biological degradation and thermal treatment.

Plasma Technologies for Environmental Protection

Efficient approach to the treatment of toxic and hazardous wastes is offered by thermal plasma. Because the arc plasma provides the means to operate the processes at much higher temperatures that are commonly achieved with conventional combustion it can be used to the treatment of the most stable chemical compounds. The target applications of thermal plasma technology are: treatment of the most toxic and hazardous wastes, clean fuel generation from waste and disposal of leftovers coming from conventional incineration plants and nuclear power stations. Some of the research results achieved in the Plasma Technologies & Environmental Protection Group at the Technical University of Lodz are here presented and discussed.